How to write a Surv object to a csv-file?

Dear David!

Thank you for your response. I like csv files, because in that case I can 
easily compare different versions of similar data.frames. Similar in this 
case means that I may add a column or change some transformation command for 
one column. With dput it's rather difficult, and when I tried the compare 
package, I had no success comparing data.frames containing Surv objects.

mat <- as.data.frame( lapply( df.soac, unclass ) )
write.csv(mat,'mat.csv')
read.csv('mat.csv')

Thanks again

Heinz

At 22:31 19.12.2008, David Winsemius wrote:

On Dec 19, 2008, at 2:04 PM, Heinz Tuechler wrote:

Dear All,

trying to write a data.frame, containing Surv objects to a csv-file
I get
"Error in dimnames(X) <- list(dn[[1L]], unlist(collabs, use.names =
FALSE)) :
  length of 'dimnames' [2] not equal to array extent".

See example below.

May be, I overlooked something, but I expected that also data.frames
containing Surv objects may be written to csv files.

Is there a better way to write to csv files?

Yes, if the goal is creating an ASCII structure that can be recovered
by an R interpreter:

?dput
?dget

 dput(df.soac, "test")
 copy.df.soac <- dget("test")
 all.equal(df.soac, copy.df.soac)

  Doesn't give you a result that you would want to read with Excel,
but that does not appear to be your goal. You can examine it with a
text editor.

--
David Winsemius

Thanks,

Heinz T?chler



###   write Surv-object in csv-file
library(survival)
## create example data
soa <- Surv(1:5, c(0, 0, 1, 0, 1))
df.soa <- data.frame(soa)
write.csv(df.soa, 'df.soa.csv')    ## works as I expected
read.csv('df.soa.csv')              ## works as I expected

df.soa2 <- data.frame(soa, soa2=soa)
write.csv(df.soa2, 'df.soa2.csv')  ## works as I expected
read.csv('df.soa2.csv')            ## works as I expected

char1 <- letters[1:5]
df.soac <- data.frame(soa, char1)
write.csv(df.soac, 'df.soac.csv')  ## generates the following error
message:

Error in dimnames(X) <- list(dn[[1L]], unlist(collabs, use.names =
FALSE)) :
  length of 'dimnames' [2] not equal to array extent

df.csoa <- data.frame(char1, soa)
write.csv(df.csoa, 'df.soac.csv')  ## generates the following error
message:

Error in dimnames(X) <- list(dn[[1L]], unlist(collabs, use.names =
FALSE)) :
  length of 'dimnames' [2] not equal to array extent


platform       i386-pc-mingw32
arch           i386
os             mingw32
system         i386, mingw32
status         Patched
major          2
minor          8.0
year           2008
month          11
day            10
svn rev        46884
language       R
version.string R version 2.8.0 Patched (2008-11-10 r46884)

 sessionInfo()

R version 2.8.0 Patched (2008-11-10 r46884)
i386-pc-mingw32

locale:
LC_COLLATE=German_Austria.1252;LC_CTYPE=German_Austria. 
1252;LC_MONETARY=German_Austria. 
1252;LC_NUMERIC=C;LC_TIME=German_Austria.1252

attached base packages:
[1] splines   stats     graphics  grDevices utils     datasets
methods
[8] base

other attached packages:
[1] survival_2.34-1